The splendid hollyhock, a long-living perennial, makes a great background accent for a flowerbed. Its large single or double blooms, up to 5 inches across, are colorful and attract butterflies to your garden. They are also a beautiful cut flower for bouquets indoors. Once established, hollyhocks are easy to maintain by following these tips.
Plant Hollyhocks in a Suitable Location
Hollyhock's relish full sunlight with balanced soil that drains efficiently. If starting from nursery stock, plant them 18 inches apart. If growing from seeds, thin out the seedlings to separate them by the same distance. A building wall or fence behind them will help protect the long stalks from wind damage. If there is no wall or fence nearby, support them once they reach 3 feet in height by securing them to bamboo stakes, 1 inch in diameter and up to 7 feet tall.
Water Hollyhocks Regularly
Water regularly, a few times a week, and daily in very hot dry weather. Water in the early morning to give the plants a chance to absorb the moisture. While drought-resistant, hollyhocks can become subject to Japanese beetle infestation if they dry out too much.
At the other end of the scale, too-moist soil can cause a fungal infection called hollyhock rust, which can destroy the plant by the end of one season. Hollyhock rust turns the leaves yellow and spotty with brown swellings on their undersides. Dig out all infested plants and burn them well away from the garden. Mix coarse sand and fine gravel into the soil to help dry it out and eliminate the disease spores. Do not plant anything in the area for at least one full season.
Hollyhocks benefit from a phosphorus boost fertilizer in the early spring to promote blooming. During the summer, light fertilizing with an all-purpose solution such as 10-10-10 will maintain both flowers and foliage. Apply it following the producer's instructions on the container.
Plant hollyhocks with lilies and dahlias, which also thrive as cut flowers.
Remove Spent Blossoms
Deadhead the spent flowers from late spring to late summer to promote more blooming into the early fall. Pinch off the blossom just above its supporting leaves. If you let the hollyhock start its seed formation too soon, it stops blooming. In early September, allow seed formation to start. The new seeds will self-scatter abundantly in the garden. Collect the seeds from the seed pods if you want to plant them in another area of the garden.
Prune Your Hollyhocks
In late June, check your hollyhocks for leaves that are yellowing or have insect infestation. Remove these and discard in the trash; do not compost. Cut back the oldest, woody branches with sharp pruning shears.
Winterizing Your Hollyhocks
Cut the stems down to the root crowns once they have turned brown following a hard frost. Apply a 1-inch thick layer of dry mulch, like hay or cedar chips, before the first snowfall to protect the hollyhock roots. Rake away the mulch in early spring as soon as the first shoots peek up through the soil.